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MG MGB Technical - fuse size

Hello all,
I'm adding several in-line fuseholders to supplement the fusing in a 67 BGT. Without me having to test each with an ammeter in series, can anyone tell me what size fuses to use in line with an SU fuel pump, rear window defroster, and D-type overdrive.
Once again (and continually) thanks for the help.
RichB
RichB

Rich,

I went with 10amp Buss fuse for my D type overdrive.
Paul Hanley

Rich - You should size the fuse for the wire, not the item at the end of the wire. Both the O/D and the fuel pump should be fine on 10 amps. Good luck - Dave
David DuBois

Standard 17 amp rated 35 amp blow, or the nearest you can get, in everything. With one exception MGB fuses are to protect the wiring and not the component. If you stick to the standard rating you have (or should have) two spares in the fusebox.
Paul Hunt

Thanks for the responses. I'm a bit confused by them, though. For example, in theory, if the fuel pump draws one amp during normal use, and the wire can handle 9 amps, putting in a 10 amp fuse will save the wires, but the pump will be seriously melted-down! If I put in a 2 amp fuse, it will blow long before the fuel pump OR the wires get very hot. If I reason this further, with a 10 amp fuse, the fuel pump would be the fuse for the wiring!
I've always fused circuits just over the point of the weakest component, not the strongest.
Puzzled,
RichB
RichB

Paul, as you say the manuals say 17amp rated 35amp blow. When buying fuses they dont appear to be marked like this but 10amp or 35amp etc. Are these the ratings or the blow ampage? i.e which should one buy?
Robert Brandreth

This thread was discussed between 29/04/2004 and 01/05/2004

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